Everyone has a huge personal goal they want to accomplish--a big, challenging, amazing goal. They think about it, dream about it, obsess about it... but they never accomplish it.

That could be because they also talk about it.

According to studies like this one, people who talk about their intentions are less likely to follow through on those intentions.

Say you want to thru-hike the Appalachian Trail, a grueling five- to seven-month trek from Georgia to Maine. (Having completed about 2% of it, I'm not so well on my way.)

You're having dinner with friends, and you tell them about it.

"Oh, wow!" one exclaims. "That sounds amazing. But won't it be super hard?"

Indeed it will, you say, and you share what you know about tent sites, shelters, too-occasional showers, and the cool trail name you'll get.

It's fun. It feels awesome to bask in the glow of people who admire you for wanting to take on such a huge challenge.

It feels like you're already on the Trail.

It also means you're less likely to actually be on the Trail someday, because "when other people take notice of an individual's identity-related behavioral intention, this gives the individual a premature sense of possessing the aspired-to identity."

In short, you already got a kick out of people thinking of you as a Trail hiker... so now you're less motivated to actually be a Trail hiker.

Sounds counterintuitive, right? Aren't we supposed to share our intentions so other people can help support and motivate us?

According to NYU psychologist Peter Gollwitzer, one of the authors of the study, that's not the case.

Gollwitzer thinks the issue lies in our sense of identity. Each of us wants to be certain things, and we naturally declare those intentions, even if we have not yet become those things. (Check out Twitter profiles bios if you don't believe me--tons of people are motivated, innovative, creative, passionate, and unique gurus, ninjas, and connoisseurs.)

Describing how I plan to run a marathon, and how I bought running shoes and joined a gym and created a training plan, certainly makes me feel good... but it also makes me feel like I'm already part of the way there even though I haven't trained at all.

Declaring what we want to be and how we will get there causes us to somehow feel we are farther along the path of becoming who we want to be, and therefore less motivated--even though we've actually done nothing but talk.

So try it. Pick a goal. Create a plan to achieve it. Then keep your goal and your plan to yourself. Focus solely on doing the work required to achieve your goal.

Then, when you do, feel free talk all you want. You've earned it.

The opinions expressed here by Inc.com columnists are their own, not those of Inc.com.